From mboxrd@z Thu Jan 1 00:00:00 1970 From: Heiko Schocher Date: Wed, 10 Feb 2010 08:03:21 +0100 Subject: [U-Boot] [PATCH v2] [PATCH] doc: add README for CONFIG_HWCONFIG option In-Reply-To: <201002091244.09504.vapier@gentoo.org> References: <4B717636.8060203@denx.de> <201002091244.09504.vapier@gentoo.org> Message-ID: <4B725A39.4040806@denx.de> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Signed-off-by: Heiko Schocher --- changes since v1: - spelling check from Mike Frysinger, thanks! doc/README.hwconfig | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 51 insertions(+), 0 deletions(-) create mode 100644 doc/README.hwconfig diff --git a/doc/README.hwconfig b/doc/README.hwconfig new file mode 100644 index 0000000..a4f489a --- /dev/null +++ b/doc/README.hwconfig @@ -0,0 +1,51 @@ +To enable this feature just define CONFIG_HWCONFIG in your board +config file. + +This implements a simple hwconfig infrastructure: an +interface for software knobs to control hardware. + +This a is very simple implementation, i.e. it is implemented +via the `hwconfig' environment variable. Later we could write +some "hwconfig " commands, ncurses +interface for Award BIOS-like interface, and frame-buffer +interface for AMI GUI[1] BIOS-like interface with mouse +support[2]. + +Current implementation details/limitations: + +1. Doesn't support options dependencies and mutual exclusion. + We can implement this by integrating apt-get[3] into Das + U-Boot. But I haven't bother yet. + +2. Since we don't implement a hwconfig command, i.e. we're working + with the environement directly, there is no way to tell that + toggling a particular option will need a reboot to take + effect. So, for now it's advised to always reboot the + target after modifying the hwconfig variable. + +3. We support hwconfig options with arguments. For example, + + set hwconfig "dr_usb:mode=peripheral,phy_type=ulpi" + + This selects three hwconfig options: + 1. dr_usb - enable Dual-Role USB controller; + 2. dr_usb_mode:peripheral - USB in Function mode; + 3. dr_usb_phy_type:ulpi - USB should work with ULPI PHYs. + +The purpose of this simple implementation is to refine the +internal API and then we can continue improving the user +experience by adding more mature interfaces, like a hwconfig +command with bells and whistles. Or not adding, if we feel +that the current interface fits people's needs. + +[1] http://en.wikipedia.org/wiki/American_Megatrends +[2] Regarding ncurses and GUI with mouse support -- I'm just + kidding. +[3] The comment regarding apt-get is also a joke, meaning that + dependency tracking could be non-trivial. For example, for + enabling HW feature X we may need to disable Y, and turn Z + into reduced mode (like RMII-only interface for ethernet, + no MII). + + It's quite trivial to implement simple cases though. + -- 1.6.2.5 -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany